1. Field of the Invention
The present invention relates to a sheet to which various desired functions such as the discharge of radiation ray at a comparatively low level and the action of photocatalyst are added. In the present specification, a sheet to which a desired function is added thus is called as a “functional sheet”. Additionally, the representation of “functional ---” means that a desired function is imparted to an “article” which a terminology of the second element inserted in the portion of “---” indicates. More specifically, the present invention relates to a functional sheet which can be used for obtaining, for example, health-promoting effect, relaxation effect, antibacterial and deodorization effects, and the like, which are obtained by irradiation of radiation ray at a comparatively low level, by generation of minus ions, and the like.
2. Description of the Prior Art
Various functional fiber products in which a desired function is imparted to a fiber product (for example, a cloth) have been conventionally developed. As one example, there exist a functional fiber product, in which far infrared ceramics generating far infrared rays, tourmaline generating minus ions, and the like are finely pulverized to be kneaded in fiber materials such as a nylon and a polyester or to be supported by nonwoven fabrics, in order to add functions such as the promotion of blood circulation by far infrared rays, improvement of immunizing power by generation of minus ions, and other health-promoting effects, removal of a harmful substance, and deodorization. Alternatively, there exists a functional fiber product in which the powder of an adsorptive substance such as zeolite and bincho charcoal is dispersed in nonwoven fabric for purpose such as removal of a harmful substance, deodorization, and the like, by adsorptive action. The functional fiber products having various functionality, thus obtained are used as clothes, bedclothes, accessories, various filters, and the like.
As an example, in “Product development with minus ion fibers,” The Senken Shimbun, Jun. 12, 2001 discloses a fiber product, in order to obtain relaxation effect and/or improve vital function, in which bincho charcoal, specific ceramics, tourmaline, and the like are kneaded in raw material for a synthetic fiber. Alternatively, a fiber product using raw thread obtained by finely pulverizing a mixture of natural ores such as granitoid or schiller rock containing rare-earth elements, and by kneading the pulverized mixture in polyester or raw material for rayon.
Although various functions are added in these functional fiber products in accordance with property of powder component kneaded or supported in the fiber, any of these functional fiber products is inferior in its efficiency.
For example, in case of a fiber product for adding function of adsorbing a harmful substance and/or an odor component, and the like by supporting a porous substance such as bincho charcoal or zeolite among the fore-description, since the porous substance such as bincho charcoal and zeolite is an “adsorptive substance” which catches and removes a harmful substance and/or an odor component, and the like in pores, the fiber product does not carry out adsorption once the product catches a harmful substance and/or an odor component and the like in pores.
Further, among the fore-description, far infrared ceramics is added or supported with a purpose of, by generating far infrared rays and irradiating the rays, for example, to human body, thus adding functions such as the improvement of stiff neck or feeling of cold by promoting blood circulation, but the far infrared ceramics generates only trace amount of infrared rays under a condition in which thermal energy is not added to the far infrared ceramics, therefore the effect has limitation. Accordingly, if the far infrared ceramics is used alone, little effect is expected.
Further, tourmaline, which is called as an electric stone, generates minus ions and thereby, is added or supported with a purpose of adding function of relaxation effect and/or improvement of vital function, and the like, but vibration is required for generating minus ions.
Thus, the functional fiber products, in which the fore-mentioned substances are kneaded or supported, requires to be used under an environment satisfying a certain condition for obtaining a desired effect, but any of the fore-mentioned functional fiber products is inferior in efficiency, and high effect cannot be obtained.
On the other hand, a functional fiber product, in which powder of ores (for example, monazite and the like) containing a radioactive rare-earth element such as thorium (Th) is kneaded in a fiber material of a synthetic fiber product to generate radiation ray, is also developed, and the functional fiber product can radiate radiation ray without addition of energy from the outside.
However, the treatment of such radioactive substance must be generally out of the application range of the Radiation Hazards Prevention Law which is a safety standard in Japan (a case that concentration and quantity are comparatively little), and there is limitation for concentration and the like at which the radioactive substance can be supported to the functional fiber product and the like (as an example, the concentration in a solid is 370 Bq/g or less). Accordingly, there is also limit for effect obtained by the functional fiber product.
On the other hand, when the concentration, quantity, and the like of the radioactive substance supported in the fiber product is much, there is a fear that radiation hazard is generated.
Further, the fore-mentioned functional fiber product, in which forecited monazite and the like are kneaded in a fiber material, requires that ores such as monazite is finely pulverized to a level at which the ores can be kneaded in the fiber material of a synthetic fiber, and there are problems that production cost is high and that life time is comparatively short.
Further, in addition to the fore-described ores, a photocatalyst substance such as titanium oxide is known, and there is also developed a functional fiber product which has functions of generating minus ions and decomposing harmful substances, and the like by supporting the powder of the photocatalyst substance in a fiber product.
However, a general photocatalyst substance is called as “anatase type”, and exercises photocatalyst function of generating minus ions and decomposing harmful substances, and the like in reaction with an ultraviolet component among light when the photocatalyst substance is irradiated by light, and since the photocatalyst substance hardly react with light in the visible light region, the fore-mentioned action is not exercised in room or dark place. Accordingly, the use of the functional fiber product is limited.
To the contrary, in Japanese Patent KOKAI (LOPI) No. 2002-85981 (hereinafter, referred to as “prior art”), as a photocatalyst substance exercising photocatalyst function in response not only to ultraviolet rays but also to electromagnetic wave with a longer wavelength than ultraviolet rays (γ-ray, X-ray, lights such as ultraviolet rays, visible light and infrared rays, and electric wave), there is also developed a photocatalyst substance described later in detail formed by a metal coating which has a tilting structure (in the present specification, called as the “oxygen deficit tilting structure”), of which oxygen to be bonded is decreased as goes from a surface to the inside gradually, on the surface of a treated product comprising a metal, ceramics or a mixture thereof.
In functional fiber product which are composed as above, for example, when clothe, for example, an underwear and the like, is produced from functional fiber products supporting powders, such as bincho charcoal, far infrared ceramics, and tourmaline, which require external addition of heat and vibration energy for the generation of far infrared rays or generation of minus ions, and when a person wears the clothe for the promotion of blood circulation of the human body, these functional fiber products can utilize only limited energy such as body heat and cannot adequately make use of the effect, since these functional fiber products are used in a condition in which they are shielded from the outside by outer wears and the like which are worn over the functional fiber product.
Since the photocatalyst substance, equipped with an oxide coating film having the oxygen deficit tilting structure shown in the prior art, exercises a photocatalyst function in response to electromagnetic wave with a longer wave length than ultraviolet rays, the photocatalyst reaction can be generated by receiving the irradiation of electromagnetic wave which passes outer wears, even if the product is used in a condition in which the product is shielded from the outside by outer wears and the like, but the reaction is not also occasionally carried out adequately in this case.
Further, since in the photocatalyst substance described in the prior art, for example, an oxide coating film is formed on the surface of a treated product by injecting a metal powder being the oxide coating film on the surface of the treated product by a blast method and the like. Thereby, the shape and size of the photocatalyst substance produced is limited by the shape or size of the treated product. Further, since it is difficult for a minute object such as powder to be used as a treated product and to form an oxide coating film on the minute object, the photocatalyst substance obtained is a comparatively large size.
As a result, as mentioned above, it is difficult to obtain a photocatalyst with a powder size which can be supported in a functional fiber product, and it is difficult to enlarge a specific surface.
On the other hand, the functional fiber product, in which the powder of ores containing a radioactive substance such as monazite that contains a rare-earth element such as thorium (Th), for example, is supported, can radiate radiation ray without input of energy from the outside, but as mentioned above, since there is a limit for the amount of powder which can be supported, the product cannot exercise various functions in high efficiency.
Accordingly, the present invention is achieved for solving defects in the above-mentioned conventional technology, and it is the purpose of the present invention to provide a functional fiber product which can make powder supported exercise desired functions in high efficiency without input of energy from the outside, and which is hardly subject to limitation by use condition and the like of the product.